Human skin-derived mesenchymal stem cells induce the differentiation of naive helper T cells into FoxP3+ regulatory T cells without CD28-costimulation

摘要

W e have found that phenotypically defined, plasticadherent human dermal mesenchymal stem cells (MSCs) have immunomodulatory capacities. To unravel, wheth er regulatory T cells are involved, total adherent dermal cells, adherent dermal MSC subsets and, as a control, bone marrow derived (BM ) MSCs, which all lack the expression of CD80/86, were subjected to functional in vitro assays with CD25 depleted naive helper T (Th) cells and stimulation with |áCD3 or |áCD3/CD28 mAbs. Using flow cytometry, T cell proliferation was visualized via carboxyfluorescein succinimidyl ester dilution and the differentiation of dividing cells into regulatory T cells was evaluated by counterstaining of the transcription factor FoxP3. Stimulation of naive Th cells with |áCD3/CD28 and coculture with dermal cells or BM MSCs led to a marginal increase of FoxP3 expressing T cells